Differential stage lift flow device, bellows type



June 24, 1941. A; BOYNTQN T 2,246,500

DIFFERENTIAL STAGE LIFT FLow pEJiI'cE, BELLows TYPE Filed Dec. -8, 1939 Fig: 2. 5y

ATTORNEYS;

, two valves.

VPatented June 24, 1941 UNITED STATES PATENT OFFICE DIFFERENTIAL STAGE LIFT FLOW DEVICE, d BELLOWS TYPE Alexander Boynton, San Antonio, Tex.

d Application December 8, 1939, Serial No. 308,311

(ci. 1er- 111) s claims.

My invention relates to stage lift flowing devices tor wells, the ilow being accomplished by the expansion force of air or gas.

The principal object is to start wells at ,relatively low pressures and to ilow them at low pressures and low gas-oil ratios.

Other objects are: l, to Acause the valve employed to admit and cut oil the supply of pressure fluid to seat with greater force and certainty than is now practiced in the art; 2, to automatically regulate the flow of pressure fluid in proportion to the volume thereof required to be employed to accomplish economical operation; and 3. to cause a well to iiow through either the tubing or the casing by employing the same device for both purposes. Y

In carrying out these objects. I employ a pressure-responsive metallic bellows, anchored at one end and free at the other, within a. chamber interposed between the pressure fluid and the opstanding well liquid inthe eduction conduit. The free end of the'bellows has attached vto it Each valve in the devices,whi'ch are spaced at intervals in a tube within a tube, is adapted to close and cut oif `the ow of pressure iluid from the induction conduit into the eductlon conduit at a pre-determined greater pressure existing within the induction conduit, irrespective of which conduit vmay be employed for induction or eduction.

Il attain the foregoing objects by mechanism illustrated in the accompanyingdrawing, inl

which- Fig. l is a broken side view, partly in section showing the devices in a well.

Fig. 2 is a longitudinal section through one of the flow devices.

Fig. 3 is a cross section on the line 3 3, Fig. 2. Fig. 4 is a cross section on the line 4-4, Fig. 2.

Fig. 5 is a longitudinal section oi' a modified form of valve and seat.

Fig. 6 is a longitudinal section of another modified form oi valve and seat.

Similar reference characters are employed to refer to similar parts throughout the several views.

'me column or `wen liquid which pressure'nuid' causes to stand up above the depressed liquid whether it be the tubing or the casing, will be referred to as the induction tube; and the conduit through which the liquid is expelled from the well, whether it be the tubing or the casing, will be referred to as the eduction tube.

Flow of well liquid from the well will be caused by employing this invention for the introduction of pressure fluid into the upstanding column which will be elongated by the subsequent expansion of the pressure fluid so admitted.

In Fig. 2, the body I2, -having the central longitudinal passage I2C oflthesame' diameter and in line with the passage through the tubing, may be c'ast or otherwise formed integrally with the shell I2a,` having the central longitudinal bore I2C between the sloping ends I 2b and i211. Said bore houses a metallic bellows member I3 which has a. stationary lower support i4.

The upper end of the bellows I3 is secured .upon its connection lil-by the solder or weld lila and the lower end of the bellows is secured upon The bellows upper end connection I5 has the,

packing 20 within its upper end compressed by means of the threaded engagement between the members I9 and 2| in order to seal the bellows hermetically at that end.

The connection I4, having an annular flange landed upon the internal annular shoulder iid, supports the bellows centrally of thebore I2c.

Proximate the lower end of the shell I2a, the packing I5 produces a hermetic seal 4above the annular' space I6c and the packing I1 produces a hermetic seal below-this annular space. 'Ihe packing i5 is urged upon the nether side oi.' the flanged portion of the member I4 by the sleeve I6, having the packing IT and the gland ring I'la closely engaged between it and the plug I8 by means of the threaded engagement of this plug `within the lower end of the shell I2a. The sleeve within the plug I8.

The -lower coiled spring 25 has slight clearance over the tube 24 and somewhat larger clearance within the bellows. The upper coiled spring 26 has large clearance with the tube 23 and small clearance within the bore |2c. The lower spring 25 is vinstalled under some compression between the members |4 and I9. The upper spring is installed under similar compression between the roof oi' the bore I2C and the bushing 2|.

The upper valve 23a formed upon the upper end of section 23 of the tubular valve stem, is adapted to engage upon the seat |27', vand the lower valve 24a upon the lower section 24 of said stem is adapted to close upon the seat |4a. Both valver are normally open, as shown, until closed by the lpredetermined differential.

The arcuately tapered bores |2h and |4c have the annular passages 2m and I4e, respectively,

bores a and b, because of their close clearance.-

restrict the passage of fluid and prevent the valves 23a and 24a Vfrom being forced open by sudden dropping of slugs of liquid in the eduction tube.

The clearance between the tube 23 within the lower end of the upper tapered bore |2h and the clearancebetween the tube 24 within the tapered lower bore |4c at the openings |4b may be such as the equivalent of a circular opening having a diameter oi to 3A; inch. The openings |2e, |6b, |4b and |2g may each have a diameter such as -1/4 to T16 inch, all dimensions depending, of course. upon the well conditions. such as depth, rate of ow, size of tubing, and physical properties of the liquid to be lifted.

Manifestly, a greater iluid pressure within the to stretch the bellows and seat the valve 23a; while a greater iluid pressure contacting the ex-v terior of the bellows than that inside of it will tend to compress the bellows and the spring 25 and thereby seat the lower valve 24a.

The pressure` fluid exerts the valve closing force which is opposed by the weight of the well liquid and the force required to stretch or compress the bellows and the spring resistance, depending upon the direction of the pressure uid ilow. e force required to compress or stretch the bello s is constant. Likewise, the force required to compress either one of the springs may be constant.

AThe force of the pressure iluid is constant at any In iiowing through the tubing as the eduction conduit, the valve 23a should close at a pressure per square inch somewhat greater than` the weight of the upstanding column manifested per square inch between adjacent devices, which may be spaced in the tubing at intervals of 150 to 300 feet. Such adjustment provides that the valve in an upper device will notV close until the next lower device has been uncovered to intake pressure fluid. A similar adjustment and spacing of the devices in the tubing may be employed for flow through the casing, unless the volume of liquid to be discharged through the casing is great. In that event, a diierent adjustment may be made.

' bellows than that contacting'its exterior will tend to admit more pressure iluid into the upstanding column.

The pressure fluid employed for flowing through either the tubing or the casing should have a value somewhat greater than two to three times the differential force required to seat the valves. Manifestly, increasing the value oi' the pressure uid will increase the rate of liquid flow from the well.

In owing through the tubing, the path of the pressure fluid through the device will be out of the annular space la, Fig. 1, into the tubing passage l2c', Fig. 2, via the opening |29, the chamber |2f, the annular passage |2m, the passage 24e, the annular passage |4e, the openings |4b, the inner annular chamber I 6a, the openings |6b, the outer annular chamber |60, and the internal opening I2e, in the order named.

In flowing through the casing, the path of the pressure iiuid is the reverse of that stated for owing through the tubing.

In flowing through the tubing, the force which compresses the bellows and the spring 25 to seat the valve 24a `at a pre-determined differential, is exerted exterior of the bellows, this force acting in the bore |2c through the opening |2g. The opposed force urging the valve 24a away from its seat is the resistance of the upstanding column of well liquid in the tubing exerted interiorly of the bellows acting through the opening |2e, the annular chamber l 6c, the openings |6b, the annular chamber Ita, the openings I 4b, and the annular space I 4e, in the order stated, plus the force exerted by the bellows and the spring 25.

In owing through the casing, the force which stretches the bellows and compresses the spring 28 to seat the valve 23a at a pre-determined diilerential is exerted interiorly of the bellows, this force acting through the opening |2e, the outer annular chamber |6c, the openings |6b, the inner annular chamber IGa, the openings |4b, and the annular passage |4e, in the order named. The opposed force urging the valve 23a away from its seat is the resistance of the upstanding column of liquid in the annular space 1a, Fig. 1, exerted exteriorly of the bellows through the opening |2g and the chamber |2f, Fig. 2, plus the expansive force of the spring 25.

It will be observed that the clearance between the lower end oi.' the tube 24 and the tapered bore |4c increases as the valve 23a approaches its seat |21, while, at the same time, the clearance between the upper end of the tube 23 and the tapered bore 2h is decreasing. Manifestly, these clearances become reversed if the valve movement is reversed. These tapered bores |2h and and |4c, co-acting with the straight tubes 23 and 24, throttle the pressure fluid' admitted into the upstanding column so as to permit, or tend to permit. the greatest flow thereof when either of theyi' valves are approximately half way of their travel. Both bores |2h and |4c may be straight. however, or one may be straight and the other tapered so as to meter the pressure iluid as may be desired for different well conditions. y

Since the annular space la is usually much greater than the size of'the tubing, greater volume oi' pressure iluid often will be required to flow the well through the casing. To provide such greater volume of pressure iluid, the clearance between the valve tube 23 and the bore |2h may be increased or the spring 28 may be made to thev casing flow, on account of less frictional resistance in the tubing, but means for ilowing through the casing is often valuable in cleaning out the wells; after which tubing liow can be resumed quickly if the flowing devices are adapted to flow through either the tubing or the casing.

Since the diameter of the bellows is many times greater than the diameter ofthe tubes and 24, as shown, it is evident that much greater force will be imparted to the `valves than would'result from employing the usual valve seated by the differential force acting upon the same area as that of the valves.

The installation plan in Fig. 1 will be employed to illustrate flowing either through the tubing or the casing. In employing Fig. 1 to illustrate the tubing ilow, it will be assumed that the flow line la is closed at the casing head.

x `A hermetic seal is formed between the casing l and the tubing 2 by the casing head l, proximately above the ground surface 8. The devices I2 are spaced at proper intervals in the tubing 2 by means of the couplings 2a and the female end i211, of the ow devices. In the upper regions of the well, the tubing may be enlarged, the swagednipple 5 being emplyed to connect the different sizes of tubing. The extension line 2b may lead to a production tank.

The anchor string 1 may extendto the bottom of the well 9, this string and the tubing being joined together by the nipple 6, having openings tu. communicating between the interior of the tubing and the annular space la.

The contents of the formation I may enter the well through gun perforatlons Il. level in the casing and tubing is assumed to at A.

Now, to iiow the well through the tubing, turn pressure iiuid ci proper value out of thepipeline 3 into the annular space la, it being assumed that 'I'he liquid f be the ilow line 2b is open. 'I'he pressure in the space l la will quickly close the valves 24a of the devices. The liquid in the casing will become depressed to B and will rise in the tubing to C. The upstanding column, therefore, will extend up the tubing from D to C. The device next to the base ofthe opstanding column will open its valve 24a in response to the low differential obtaining there. The corresponding valve in the second device above the base at the upstanding column either will remain closed or be partially open, depending,

lower if the rate ol liquid ilow from the well is greater than the inflow. If this occurs, the lower devices will be uncovered, in turn, and the well,

thus, will flow by stages from` progressively lowerv levels as t e flowing Aoperation continues, uncovering one device after another, until the lateral openings 6a in the nipple 8 are reached by the pressure fluid, which will then expel the upstanding column as a slug. l

It will be noted that the valves are always open at a pre-determined distance above the base of the upstanding column and that they close successively as the base of that column moves downward.

Now, to ovv the well through the annular space la, i. e. using the casing as the eduction tube, the pipe line 3 will be disconnected and replacedby a plug in the casing head. 'Ihe pipe line 2b will become the induction tube for pressure iluid and the discharge of well liquid will be through the pipeline la.

The larger size tubing shown in the upper portion of the well and the swaged nipple 5, preferably, will be replaced with tubing of the smaller size if the well is tobe flowed through the casing other than during; short periods for clean-out purposes only.

It being assumed that the well liquid in bothV casing and tubing is standing at A when the pressure fluid is turned into the tubing 2 from the pipeline 2b, the `devices will quickly close their Vvalves 23a as the pressure builds up in the tubing,

- convex, the seat Md being formed to engage this valve, while the bore Mc is uniformly tapered.

In Fig. 6, it is shown that the valve 24d may be concave to engage the seat Md', the bore I 4c' being uniformly tapered as in Fig. 5. Y

It will be understood that the valves in the sam device may be adjusted to close at the same difterential or different differentials by employing springs of different forces, and that these forces may be made to vary progressively with increasexpel the well liquid from the eduction tube by a force that would have to overbalance the entire unaerated upstanding column.

The foregoing speciilcation, drawing, and ap?- pended claims are intended to set forth the invention as fully as may be done within the limits of a patent, with the understanding that many minor changes can be made in the construction and arrangement of parts within the scope and purpose of the stated objects and allowed claims.

What is claimed is:

l. In a device for flowing'wells, a valve body,

a housing on said body, said housing having a cylindrical inner chamber with a fluid inlet at the upper end from the exterior of the valve body and a fluid outlet at the lower end communicating with the interior of said body, upper and lower valve seats in said housing, a tubular valve stem having upper and lower valves thereon adjacent said seats, and means on said stem anchored to said housing and responsive to differential fluid pressures inside and outside said body to move said stem and said valves, said meansl closing the passage of iluid through said housing lower end communicating with the iiuid opening in said body, upper and lower valve seats in said housing, a tubular valve stem having upper and lower valves thereon adjacent said seats, a bellows 'diaphragm in said housing. a support for said diaphragm having a sealing connection with the lower lend thereof, a bushing closing the upper end of said diaphragm about said valve stem, and springs above and below said bushing. said tubular valve stem furnishing a iluid passage through said housing.

3. In a device forA flowing wells, a valve body having an opening therein, a housing on said body having an upper port leading to the exterior of the housing, a lower port therein communicating with said opening, valve seats at the upper and lower ends of said housing, a tubular valve.

stem between said seats, valves at the upper and lower ends of said stem, said stem forming ya fluid passage. a diaphragm on saidstem closing/ passage of iluid through said housing except through said stem, said diaphragm being responsive to nuid pressures inside and outside the same `to move said stem and said valves.y

4, In a device for nowing wells, a valve body having an opening, a housing on said body having an upper port communicating with the exterior of the body and a lower port communicat- R ing with said opening. a bellows diaphragm having its interior open, to said lower port, a vbushing having sealing connection with the upper end of said diaphragm, a valve stem comprising upper and lower sections' mounted in said bushing. -a passage through said valve stem sections and said bushing for fluid, valve seats for the upper and cylindrical tubular valve stem between said seats,

tapered valves at each end oi' said stem, said valve stem forming a iluid passage between said ports, and means responsive to fluid pressure sealing the passage of iluld through said housing except by way of said valve stem, said valve seats having a cylindrical area adjacent thereto and a tapered area outside said cylindrical area whereby the fluid may be metered as said valve approaches said seats.

ALEXANDER BOYNTON. 

